How you gain the insight is usually less important than the means, unless the means is also a form of insight. It may be a look, a brief conversation, a seemingly meaningless exchange at a front counter, a nudge during a football game, a novel about a bank clerk in India, a hesitation, a moment when the person carefully chooses a word - all can reveal larger things if you are ready to notice.
We walk through a mist of messages, some of which we grasp immediately while most are lost forever and still others may not be clear until minutes, days or even years afterwards. "What is to be learned here?" is a key question. Others are "What is he trying to say?" and "What is she trying not to say?"
Those who proudly announce that they only give and receive direct messages are bragging of a limited vocabulary. There is so much more out there and you may find it in a book or a look.